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Bird brains



Please forgive me if you have already received this lengthy post, but I think
that I made a mistakenly failed to mail it to all on this list.  I wrote this
as a response to Steve9120 and M. Rowe concerning the intelligence of crows
and birds and dinosaurs in general.  I am very interested in your responses
since I pose questions well outside of my field of expertise.  Here is the
post:

One more example of the intelligence of crows (or perhaps ravens -- it was
many years ago when I read this) involves an experiment somewhat similar to
what M. Rowe described.  A bird was placed in an area where the only water
available was in a tube so narrow that only the bird's beak could fit inside.
 Furthermore, the water level was set so that it lay just beyond the bird's
reach.  In a brilliant solution that probably is beyond many human's problem
solving abilities, the bird dropped pebbles into the water until the water
was displaced enough for it to reach!

As far as other birds are concerned, I have heard remarkable things about
African Grey Parrots.  I read of one bird with a vocabulary of hundreds of
words that, it was claimed, idependently developed the ability to construct
simple two word sentences (i.e. the bird would say "Go gym" -- a request to
go to the gym for play after being told what "go" meant and the association
of "gym" with the gym and play).  The bird could also identify not only
objects like ball, apple, spaghetti, etc., but could identify abstract
objects on flash cards like "blue circle" and "red triangle."  According to
the researchers, its ability to accurately identify abstract objects is
beyond even the highest non-human primates. 

The intelligence of parrots and their close relatives, and crows and their
relatives (i.e. ravens and jays) is fairly widely known, but I have also
heard that pidgeons have exceeded humans on some tests where they were
trained to identify complex abstract designs transformed though reflection,
rotation, etc.  In fact, in a recent _Discover_  article it was claimed that
a group of trained pidgeons could accurately descriminate between different
styles of art.  For example, they could tell the difference between works of
Picasso and works of Matisse (spelling?).

Perhaps it shouldn't surprise us that birds are gifted in identifying objects
and patterns visually since the biggest part of their brains are the enlarged
optic lobes while for us mammals the largest part of our brains, I think, are
essentially swollen olfactory lobes.

Birds (and other dinosaurs) possess much larger ganglia (nerve bundles) in
their hip and shoulder regions than do mammals.  It's pretty well known that
when a chicken's head is cut off, the body still possesses the ability to
flap and run.  What I have been wondering about is if these ganglia act like
regional "co-processors" that off-load some of the motor control from the
brain.  I don't suggest that birds and dinosaurs "think" with these areas,
but that a level of gross motor control may occur there requiring only simple
commands from the brain like "run" or "fly fast."  This type of operation
would be especially useful in animals like birds because it would mean the
brain could be smaller and the weight from an advanced nervous system could
be distributed more evenly and not make the bird quite so top-heavy.  This
type of nervous system might also prove useful to dinosaurs: in a large beast
the ganglias might enable quicker and more complex responses to stimuli.
 Since it could take several seconds for a message to be sent from the brain
to the tail along normal pathways, by narrowing the bandwidth of messages
sent from the brain, it might be possible to send these messages more
quickly, and send more complex commands enabling the large animal to be
quicker and more coordinated than one might otherwise expect. 

Parrots and ravens already have big brains.  If I recall correctly, in
comparison to their body weight, their brains exceed most mammals. Perhaps
because they "think" with what is effectively the optical processing parts of
their brains which would presumably work differently and, not unconceivably,
more efficiently than the olfactory regions we think with, birds may not need
brains as large mammals' to be equally "intelligent."  Also, the existence of
ganglia might suggest that the brain could be smaller still while off-loading
some of its functions elsewhere.  

I am well outside of my field in this message and welcome any suggestions
and/or corrections to any of my ideas presented here.

V. Smith